From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Martin K. Petersen" Subject: Re: bloated workload of SCSI commands at attachment Date: Thu, 14 Dec 2017 22:02:22 -0500 Message-ID: References: Mime-Version: 1.0 Content-Type: text/plain Return-path: Received: from userp2130.oracle.com ([156.151.31.86]:57226 "EHLO userp2130.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754775AbdLODC2 (ORCPT ); Thu, 14 Dec 2017 22:02:28 -0500 In-Reply-To: (Douglas Gilbert's message of "Wed, 13 Dec 2017 09:21:14 -0500") Sender: linux-scsi-owner@vger.kernel.org List-Id: linux-scsi@vger.kernel.org To: Douglas Gilbert Cc: "linux-scsi@vger.kernel.org" Doug, > What seems to be to be new is the three repeated sequence involving > the "a3 0c" command. That is REPORT SUPPORTED OPERATION CODES. > Why is the same sequence repeated 3 times? One invocation is probably partition scanning. sd_probe calls revalidate twice. It used to be a somewhat tricky dance of doing it once to get basic device properties, then allocating the gendisk, and finally doing another revalidate pass to fill out the remaining fields that had a dependency on a gendisk being instantiated. Given some of the recent block changes, I am not entirely sure two calls are required. Would be interesting to test... -- Martin K. Petersen Oracle Linux Engineering